As a rule, the cooling elements of the cooling apparatus through which the hydraulic fluid flows and which are combined into a package consist of aluminum plates and rods, which are surrounded by air fins and are connected with a box-shaped distributor section extending over the top of the package. An installed fan furthermore acts on the cooling elements.
To avoid the necessity of having to stock connectors of different dimensions for different models of cooling apparatus, and to make the installation of the cooling apparatus easier, the parallelepiped distributor section of the liquid treatment arrangement in accordance with EP 0 983 475 B1 is provided in a corner area with a flattened section, in which a passage for a liquid is provided. Furthermore, a hollow adapter cap is provided, which can be placed on this flattened section and is substantially pyramid-shaped and has a base with a passage for a liquid, which corresponds to the passage for the liquid in the flattened section, and a pipe line connection. This allows the installation of the adapter cap on the flattened corner section at different orientations in such a way that, depending on the requirements, the pipe line connector is pointed to the rear, upward or to the side. At the same time it is possible to stock different adapter caps, which are matched in respect to diameter and screw thread to the connecting opening of the pipe lines to be connected, so that in an economically advantageous manner it is necessary to produce and keep in stock only a single model of the liquid treatment arrangement. The content of EP 0 983 475 E1 is hereby incorporated by reference.
However, a problem in regard to this connecting device and its adapter cap resides in that it is necessary to install and connect the temperature sensor required for regulating the cooling apparatus separately at some location of the hydraulic fluid line, or in the cooling apparatus itself, which is relatively expensive constructively and in view of installation technology, and requires a refinishing of the screw threads following the heat treatment, because of which the cooling apparatus can become contaminated by dirt.